Centrifugal fan.



5.3. WILLIAMS.

GENTBIFUGAL FAN.

, APPLICATION FILED 1320.6, 1909.

Patented Sept. 9, 1913.

Edvard ET:-

WiC aesses: a

5 of Massachusetts, have on nassscnonnhre, assxoson son .fjeyqeiiicattcn of Letters rstent.

Patented deans oss fication sinseaenzeissa as menses.

2 b "23 whom it may concern.

known that I, Eoomm B. Wnmaus, a citizen of the United States, residing at Boston, in the county of Suflolk and State invented certain new and useful Improvements in Centrifw. goi Fans; and I do hereby declare the fol.- lowins tabs :1 fulh-clesr, and exact descriptzon of the invention, such as will enabis others skilled-in the art to which it'ap pertains to make and use the same. .c invention relates to centrifugal fans Whici'i take the air in axially it cironmierentiaiiy oi the fan wheel, and more; particularly to a fan of this character in which there is sires discharge oi the air nli about the periphery or the wheel, as dis tinguishcd from :1 ion in which the wheel is surrounded by a scroll'oasing having a tangential outlet for the air.

The a fan of this character having a novel and oved construction and mode 0i Q eraiierebyite eT-iaicncy in handling ergo. oluznes of air and producing a high suction 'or'prcssurewhen operating at high spec-d is incrcn ed.

To this end the invention consists-in the features of construction and combinations M hereinafter described and set forth in the claims.

'IJho dentures oi the invention will he readily understood from an inspection of the accompanying drawings, and the following detail d description of the fan shown therein.

in the drawings Figure 1 is a front elevation of the fan embodying the invention, and Fig. 2 is avertical section on line 2--2, Fig. 1.

As shown in the drawings, the wheel of the an is rovided with a central conical hub l whic is secured to the shaft 2. A back plate 3 is secured to the rear side of the hub 1, and a series of fan blades 4 are secured in any suitable manner to the back plate and hub. The blades iare comparatively narrow axially, and extend from the circumference of the wheel substantially in to the shaft on which the wheel is supported since it has been found that this form oi blade increases the ciiiciency of the ion. The

front edges of the blades are preferably in-' ciincd toward the rearof the :Ean,- so that s ado em is less near the axis 103? the.

and dischargeobject of the invention is to providev fan-than it is at the p riphery of the inlet (Eye. This also adds to. the efsciency of the since there is less air entering and gassing along the blades at the axis of the than therein toward its circumference. The in enters the wheel through an eye 5, and the flange or ate 6 forming the eye is 'frustowonical in s ape, so that a tapered or conical inletguide is formed about the eye.

This conical inlet eye receives the inflowing an and guides 1t axially through the eye in an 'eficient manner.

On the rearwardly inclined front edges of theblades 4 is a ring 8 which connects the front dges of the blades together, said ring extendinginwaldly in parallel relation with the inwardly converging portion of the plate 8.- The ring a together with the. back plate 3 from a contracted threat at the discharge end of each fan section which "directs the airalong the. converging faces of the plates 7 and 8 in arm-outward direction and free from cross currents or eddies. The

'airjeuteri atlas fan wheel is carried around y es, and 1s thrownoft circumfer- .ent1a1ly..from the fan wheel about the circumferenceof the fan. The flow of the air oil the ends of the blades is in a general tangential direction, the angle which the currents of air make with the tangent at the point of discharge depending upon the shape of the blades. In order that this angle may beincreased, the blades are curved rearwardly toward their outer ends. Since the air is thrown outwardl e of the fan Wheel witii a certain force and vs ocity against the pressure of the surrounding air, the efiiciency of the fan will be increased by increasing the radial component of the force tending to carry the air away from the' periphery of the fan. i have found thatthe efiiciency of a fan of this character is greatly increased by arranging stationary ides on o posits sides of the fan wheel etween wli thrown oii' by the wheel is directed out into the surrounding-atmosphere. To secure the best results, these stationary guide plates should converge toward their outer edges, so that the circumferential area between the two blades is substantially the same, whatever the distance from the axis of the wheel. These stationary plates probably add to the efiioiency of the fan by oiiering a frictional about the periphich the air resistance to the circumferential movement with a resulting of the air, so that they operate to change the direction of the flow of the air and render it more nearly radial to the wheel. The air is therefore discharged from between the plates more. directly against the inward pressure of the surrounding atmosphere,

decrease in the power required to drive the wheel, and an increase in of air handled by it. 7

As shown, the stationary guide plates between which the air is discharged consist of a disk 7 arranged back of the fan wheel, and a frusto-conical plate 8 connected with the guide plate 6, and arranged at the frontof the wheel. These plates converge toward their outer edges, so that the area of the the efliciencv of the wheel and in the volume discharge passage between the plates remains substantially constant. These plates may be supported in fixed position with relation to the fan wheel in any manner best suitedto the conditions under which the fan is to be used.

\Vhile it is preferred to employ the specific construction and arrangement shown and described, it will be understood that this construction and arrangement is not cs sential except-50 far as specified inthe claims, and may be varied or modified without departing from the invention.

Having-explained the nature and object of the invention, and specifically described one V form of fan in which it may be embodied, what I claim is 1. A centrifugal fan comprising a front :plate havinga frusto-conical eye and an inwardly converging portion of the front plate, substantially as set forth.

' 2. A centrifugal fan comprising front and rear plates having inwardly converging rim portions, the front plate provided with a frusto-conical eye', a fan wheel between said plates, provided with radial blades havingrearwardly inclined outer front edges, a

a ring mounted onthe inclined front edges of said blades and connecting said blades to gether and forming contracted throats at the discharge ends .of each fan section adapted to discharge the air in linewith-the converging inner surface substantially as set forth.

' EUGENE B. WILLIAMS.

Witnesses:

MARGARET -L. GILMAN, N. D. MCPHAIL.

Copies of this patent, may be obtained for five cents each, by addressing the Commissioner of Patents,-

Washingtqn,l).0. i

1 circular plate on the rear of said blades, and

of the front I ,plate, 

